Method for quenching fluids



June 8, 1948. B. G. MAGUIRE METHOD FOR QUENCHING FLUIDS Filed July 2,1945 INVENTOR B. G MAGUIRE BY ATI' OR EYS Patented June 8, 1948 UNITEDMETHOD FOR QUENCHING FLUIDS Bernard G. Maguire, Kansas City, Mo.,assignor to Phillips Petroleum Company, a corporation of DelawareApplication July 2, 1945, Serial No. 602,884

2 Claims. 1

This invention relates to the quenching of hot hydrocarbon fluids. Inone of its more specific aspects it relates to an improved method forquenching hot hydrocarbon fluids by th use of an improved quench oilinjection fitting. My improved fitting may be used for the quenching ofhot vapors as well as for the quenching of hot liquids in transit.

Quenching devices for the instantaneous cooling of liquids, or for therapid cooling of vapors with or without condensation are common in theart. The main object of most older quenching methods has been withrespect to the speed or rapidity ofv the cooling, and for the most part,apparatus which promoted the more rapid cooling or quenching wasconsidered to be the more desirable.

I have found in certain cases and under certain conditions that theconventional rapid quench of hot streams of fluids is a markeddisadvantage. When streams of hot, liquid, cracked hydrocarbons whichcontain tarry, coke-forming materials, are quenched, these materialstend to precipitate out due to the decrease in temperature. Quench oilsusually are relatively good solvents for such precipitated materials.If, however, the cracked stock is high in such constituents, the quenchoil may not be able to dissolve the tarry, coke-like materials as fastas they are formed. The overall result of such conditions will be adeposition of coke on the walls of the transfer line on the downstreamside of the point of quenching. Ultimately the pipe may becomesuificiently choked that a shut down and cleancut is necessitated. Toorapid cooling of vapor streams may cause similar results.

To overcome such impractical operation I have devised means forquenching or cooling such hydrocarbon streams which means accomplishesthe desired cooling and at the same time prevents coking of the transferline following the point of quench.

One specific object of my invention is to provide ,a quench fitting sodesigned as to produce as little turbulence as possible at the point ofquench.

Another object of my invention is to provide a quench fitting designedfor the addition of a quenching material in a direction as nearlyparallel as possible to the direction of flow of the fluid beingquenched.

Still other objects and advantages will-be apvide an apparatus for therapid quenching of hot hydrocarbon fluids and still prevent depositionof coke on the downstream side of the quenching apparatus.

Another object of my invention is to provide a quenching fitting for usein hydrocarbon cracking furnace transfer lines for cooling streams ofcracked oils or vapors without substantial precipitation and depositionof coky materials on the inside. walls of said transfer lines.

Still other objects and advantages will be apparent to those skilled inthe art from a careful study of the following detailed description takenin conjunction with the attached drawing which respectively describesand illustrates a preferred embodiment of my invention, and whereinFigure 1 is a longitudinal, elevational view, partly in section, showingone type of my quenching apparatus.

Figure 2 is an end view of the quench fitting looking from the line 2-2of Figure 1 in the direction of the attached arrows.

Figure 3 is a cross sectional view of the quench fitting taken on theline 33 of Figure 1.

Figure 4 is a longitudinal sectional View of a second type of quenchingapparatus.

Referring to the drawing and specifically to Figure l, numeral H refersto the quench fittin proper while numeral l2 refers to an auxiliaryfitting. The quench fitting is composed mainly of a body I3 and two endflanges I4 and it. A free and unobstructed opening it is the conduitthrough which a stream of hot fluid to be quenched flows. The fluidflows in the direction indicated.

The main body of the fitting is provided with some channels 11 throughwhich quench oil may flow. In the fitting illustrated by Figures 1, 2and 3, I have shown four of these channels. It will be obvious that thefitting member may be made to contain as many of these channels asdesired, ranging from one to any number as four, six or even eight, orin very large sized equipment a relatively large number may be required.The angle I8 which the longitudinal axes of the channels I! make withthe conduit l6 should prefr b be as small as is consistent with goodmechanical construction. The outer ends of these channels terminate inopenings l9. The inner ends of the channels terminate in slots 20adjacent the fluid conduit. The flange l4 contains bolt holes forsecuring the fitting member to its operating position in a fluidcarrying transfer pipe. Since the endflange I5 is of a greater diameterthan is normal for the conduit It, the auxiliary flange reducing fittingI2 is used, and this fitting terminates in a flange .2I to which ma beattached pipe fittings of standard dimensions. Thus in the overallinstallation of my quenching apparatus, the assembly illustrated inFigure 1 is simply inserted into a transfer line at a point at which itis desired to quench the fluid in transit.

As an alternative the auxiliary flanged fitting l2 may be omitted ifother means is available for attaching the large end flange Hi to theflange of a transfer pipe 22. This auxiliary flanged fitting l2 servesno purpose as regards the quenching operation, but is merely a reducingflange. The joint between this reducing flange l 2 and the flange i5 issealed by use of a gasket 23.

The quench fitting embodiment illustrated in Figure 4 is intended tofunction in substantially the same manner as does the embodiment ofFigure 1. The only difference is in its mechanical construction. InFigure 4, the quench member is composed of two parts, these beingidentified by reference numerals 25 and 26. The outer housing member 25is composed of a standard diameter flange 21, an outer conical shapedhousing 28, and a large diameter flange portion 29 coring holes 30threaded to take pipe fittings. The inner member 26 is composed of twoparts identified :by numerals 3| and 32. The conical portion referred toby numeral 3| may be considered what would be left from a cone by havingits longitudinal axis drilled out and the base of the remaining annularportion attached to a flange, identified by numeral 32. With this typeof quencher a reducing flange I2 is needed in like manner as wasexplained in reference to Figure 1. This reducing flange and the quenchmember are held in fluid tight contact by bolts 34 and a gasket 35. Afluid tight seal is also necessary between the flanges 32 and 29, andaccordingly a gasket 33 is inserted. The several large diameter flanges29, 32 and flange member l2 may be held together by a single set offlange bolts, as bolts 34.

As mentioned hereinbefore, my apparatus may be used in the quenching ofhot vapors as well as for quenching hot liquids. In either case, thequench fitting H or 25 and a reducing flange member 52 are merelyinserted into a transfer line at the desired point of quench.

For the quenching of hot liquids in transit, a quench oil or otherdesired liquid is forced through the quench oil inlets IQ (of Figure 1),into the fittings against transfer line pressure. The oil flows throughthe channels I l and enters the conduit it at points 20. The quench oilentering the conduit [6 is swept in a downstream direction by the hotoil to be quenched. Since the quench oil enters the conduit I6 at arelatively small angle with the conduit, mixing of the two oils isslight, and for the most part the central core of hot oil and the addedquench oil fiow downstream in substantially a streamline manner. Theslot openings'Zll are intended to be of such length that four of them asshown in Figures 1 and 2 cover substantially the entire circumference ofthe conduit 16. Thus the relatively cool quench oil entering the conduitl6 through the slots 20 forms a layer of cool oil adjacent the side wallof the transfer pipe.

While the quench oil follows the pipe walls for quite some distancebefore mixing with the hot oil in transit, yet the time period prior tocomplete mixing is relatively short since hot oil transfer linevelocities are rather high.

These quench fittings may be used for adding quench oil to streams ofhot vapors as well as to liquids or even to streams containing liquidsand vapors. The mechanism of operation of my quench fitting in theseseveral cases is substantially the same, that is, cool quench oil entersand is carried downstream adjacent the pipe walls.

While quenching liquid is in transit slowly, tarry and coke-formingconstituents are precipitated rather slowly due to a relatively slowdrop in temperature. In addition, little turbulence is caused at thepoint of quench because the direction of flow in the transfer line isnot changed. The inner diameter of the transfer conduit is not changedas is the case when using conventional quench fittings. The quench oilon flowing downstream in a streamline manner sweeps the walls of thetransfer line and prevents deposition of coke and coke-formingmaterials. My quenching is not immediate and in fact is intended to berelatively slow. This type of quenching results in a smallerconcentration of coke and tarry material being precipitated in the caseof liquids, and condensed in the case of vapors, per length of transferline and allows these undesirable materials to be swept away by thestream rather than to be deposited on the walls of the transfer line.

In the quenching of hot liquid or vapor streams it is believed that theactual precipitation or condensation of tarry coke-forming particlescannot be prevented in any manner. The amount of such material formedwould appear to be dependent upon the type of stock being quenched, itscomposition, temperature and pressure and quench temperature rather thanupon the speed of quench. Thus by my slow quench the precipitated tarrymaterials may be actually dissolved and/or carried away by the wallsweeping action resulting from the particular design of my apparatus.

My fitting was designed primarily to get away from the conventional Tinjection fitting wherein the quench oil and transfer line effluent meetat right angles causing what I consider undue turbulence at that point.I believe that an added advantage of my design is that the quench oilwill sweep the walls of the transfer line downstream from the injectionpoint and thereby cool the main body of the furnace eflluent over alonger section of transfer line. Since the time of quenching is longerand therefore the rate of tar and coke precipitation accordingly lessthan that involved when using conventional quench fittings, the quenchoil has less coke formers to dissolve in a given interval of time.

My fittings are suitable for use with any type of quench oil it isdesired to use. To those skilled in the art it is well known that manydifferent vapors, oils and other liquids need to be quenched for variousreasons, and I have found my fittings and the principles embodiedtherein have wide application. For example, my fittings may be used forthe quenching of high temperature oils, such as hydrocarbon oils,hydrocarbon vapors, or mixtures of liquid and vaporous hydrocarbons;water may be added to liquid or vaporous materials, or one liquidchemical to another liquid or vapor wherein final mixing should not beextremely rapid. v

My fittings may be made of any size desired depending upon its intendeduse; For example, a fitting for installation in a two inch diameter pipeshould have a conduit (16) diameter of about two inches. The size of theinlet ports l9 of Figure 1 and of ports 30 of Figure 4 will be dependentupon the volume flow of quench oil required for a given problem as wellas upon the number of such ports in the fitting. The angle between thechannels H and the longitudinal axis of conduit 16 of Figure 1 and thecorresponding angle between the annular conduit space 37 and thelongitudinal axis of the conduit 36 should be as small as possibleconsistent with good mechanical construction. The smaller this angle themore efiicient will be the washing action of the added quench oil andthe slower will be the mixing of the quench oil and the material beingquenched.

Materials of construction may be selected from among those commerciallyavailable and found to be suitable for the purpose at hand. Forcontacting one hydrocarbon oil with another, ordinary steel may servethe purpose. For handling corrosive chemicals, special corrosionresistant material should be used.

I do not wish to limit my invention in any manner by the above givenexplanation or theory as to how my quench fitting functions, since thesame was given merely as a means of illustrating the principles involvedand preferred embodiments of my invention. It will be obvious to thoseskilled in the art that many modifications in design and constructionmay be made, as well as many additional applications for its use withoutdeparting from the intended scope and spirit of my invention.

I have described two embodiments of a quench fitting which main bodymember has a conical shape or rather that of a truncated cone. Thisparticular shape or form, however, plays no part in my invention sincethe actual exterior shape or form is immaterial. This body member may becylindrical in form, or rectangular, or hexagonal, or any other form,likewise it may be conical or rather that of a truncated cone or eventhat of a truncated pyramid of as many sides as desired. The only reasonfor using the pyramidal or conical form is as a means of saving ofmaterial and therefore cost of construction.

If the body member is square or hexagonal in cross section then thechannels I! (of Figures 1, 2 and 3) may well be directly under the edgesof said figures for structural reasons.

If both ends, that is the flanged ends, of my quench fittings are of toogreat diameter to be attached to standard pipe fittings, then reducingflanges will be needed. By using a conical or pyramidal form of fittinga downstream end reducer flange will usually not be needed since thisend of the fitting will fit to standard pipe flanges. However, areducing flange mechanism will usually be required on the upstream endof my quench fitting.

What I claim is:

1. The method of quenching with a first cooler fluid, a second hotterfluid flowing in a pipe which second fluid during quenching tends toprecipitate solids on the inner surfaces of said pipe, and which solidsare relatively slowly soluble in the first fluid, which comprisespassing the second fluid through the pipe in substantially streamlinedflow, injecting the first fluid in the form of a substantially annularsleeve between the second fluid and the walls of the pipe and in adirection of flow concurrent with the direction of flow of said secondfluid, said first fluid meeting said second fluid at such a small angleof contact that substantially no turbulence at the point of injectionoccurs, confining the second fiuid and any solids precipitated thereinwithin said annular sleeve of cooler fluid until at least a coolerportion of said pipe is reached whereby adherence of said solids to saidpipe is substantially reduced, and subsequently mixing said first andsecond fluids together slowly whereby said first fluid may dissolve someof said precipitated solids before all of said solids have beenprecipitated whereby the adherence of said solids to the pipe walls issubstantially reduced.

2. The method of quenching with a first cooler fluid, a second hotterfluid flowing in a pipe which second fluid during quenching tends toprecipitate solids on the inner surfaces of said pipe, and which solidsare relatively slowly soluble in the first fluid, which comprisespassing the second fluid through the pipe in substantially streamlinedflow, injecting the first fluid in the form of a substantially annularsleeve between the second fluid and the walls of the pipe and in adirection of flow concurrent with the direction of flow of said secondfluid, said first fluid meeting said second fluid at such a small angleof contact that substantially no turbulence at the point of injectionoccurs, and that the second fluid continues to flow in a streamlinedmanner surrounded by the streamlined flow of the annular sleeve of saidcooler fluid, confining the second fluid and any solids precipitatedtherein within said annular sleeve of cooler fluid until at least acooler portion of said pipe is reached whereby adherence of said solidsto said pipe is substantially reduced, and subsequently mixing saidfirst and second fluids together slowly whereby said first fluid maydissolve some of said precipitated solids before all of said solids havebeen precipitated whereby the adherence of said solids to the pipe wallsis substantially reduced.

BERNARD G. MAGUIRE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,655,053 Fleming Jan. 3, 19281,957,946 Donnelly May 8, 1934 1,966,113 Booth et al July 10, 19342,165,880 Arkin et a1. July 11, 1939 2,310,265 Sweeney Feb. 9, 1943FOREIGN PATENTS Number Country Date 354,393 France Oct. 4, 1905 409,875Great Britain May 10, 1934 Certificate of Correction Patent No.2,442,898. June s, 1948.

BERNARD G; MAGUIRE It is hereby certified that errors appear in theprinted specification of the above numbered patent requiring correctionas follows: Column 1, line 53, strike out Still other objects andadvantages will be apand insert instead Still another object of myinvention is to pro-; column 3, line 52, for fittings read fitting; andthat the said Letters Patent should be read with these correctionstherein that the same may conform to the record oi'the case in thePatent Oflice.

Signed and sealed this 31st day of, August, A. D. 1948.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

